Next Unit
Describe the principle of operation of a simple hydraulic governor.(10)
Principle of Operation of a Simple Hydraulic Governor
A hydraulic governor is a device used to regulate the speed of an engine by controlling the fuel supply. It operates on the principle of fluid pressure and lever mechanics.
1. Engine Governor | Download Free PDF – Scribd
Key Components:
- Governor Body: Houses the governor mechanism.
- Flyweights: Weighted arms that rotate with the engine shaft.
- Springs: Counteract the centrifugal force of the flyweights.
- Sleeve: Moves up and down depending on the speed of the engine.
- Control Valve: Controls the flow of hydraulic fluid. 1. What Are The Three Types of Control Valves Used In Hydraulic Systems? www.everlastingvalveusa.com
- Hydraulic Piston: Converts hydraulic pressure into mechanical force.
- Fuel Control Rack: Controls the amount of fuel supplied to the engine.
Operation:
- Speed Increase: When engine speed increases, the centrifugal force acting on the flyweights overcomes the spring force, causing the flyweights to move outward.
- Sleeve Movement: The outward movement of the flyweights causes the sleeve to move upward.
- Control Valve Position: The movement of the sleeve alters the position of the control valve, reducing the flow of hydraulic fluid to the fuel control rack.
- Fuel Supply Reduction: The reduced hydraulic pressure causes the fuel control rack to move, decreasing the amount of fuel supplied to the engine, thereby reducing its speed.
Conversely, when engine speed decreases, the centrifugal force on the flyweights reduces, allowing the spring force to pull the flyweights inward, increasing the fuel supply to restore the desired speed.
In essence, the hydraulic governor acts as a feedback control system, maintaining a constant engine speed by adjusting the fuel supply.
Opens in a new windowdieselship.com
simple hydraulic governor
Mechanical-Hydraulic Controller
(Governor)
For say an increase in engine load the flyweights move radially inwards and pilot valve
Y moves down so allowing the servo-power amplifier (S) to move up under admitted
oil pressure. This increases the fuel control setting and also rotates feedback link AB
and reset link CD anti-clockwise about pivot A (initially fi xed as reset piston R has equal
pressures on each side).
Due to CD rotation pilot valve X moves down allowing R to move down due to oil
escape to drain. As R moves down to a new equilibrium position, AB pivots about B
and rotates CD clockwise so closing X, locking R and restoring D to its original position.
The engine is now running at original speed but at a different load. The governor is
P + I, that is, isochronous. To reduce the governor to simple proportional pivot A is fixed,
R and X eliminated and link CD removed. The conical form spring gives linearity to the
speed measuring system
Reeds Vol 10 page 195